The C-terminal DNA endonuclease region and biotechnology applications of a group II intron reverse transcriptase from Thermosynechoccus elongatus

Group II introns insert site-specifically into DNA target sites through a process termed retrohoming. They consist of a structured, catalytically active intron RNA and its encoded protein. The protein contains several domains, including a reverse transcriptase domain and a DNA endonuclease domain used for bottom-strand cleavage. Recently, the thermophile Thermosynechococcus elongatus BP-1 was found to contain eight functional group II intron-encoded proteins. The proteins are thermostable and active at temperatures up to 65°C. The intron-encoded protein, TeI4c displays the greatest reverse transcriptase activity of these eight proteins, as well as high fidelity and processivity; ideal qualities for a commercial reverse transcriptase. This work explores the possibility of using TeI4c for biotechnology applications, and specifically examines the C-terminal endonuclease domain of TeI4c and its effect on reverse transcription. Additionally, this work investigates the retrohoming activity of a TeI4c truncation that deletes the endonuclease domain.